Narrow intermediate-depth seismogenic band related to flexural strain in relatively dry Peruvian flat slab
Abstract The distribution and rupture properties of intermediate-depth earthquakes (70–300 km) provide insights into the interior stress state of the subducting plate, its petrological composition, and the subduction history. Here we evaluate the kinematic spatio-temporal rupture evolutions of four...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-02-01
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| Series: | Communications Earth & Environment |
| Online Access: | https://doi.org/10.1038/s43247-025-02071-0 |
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| Summary: | Abstract The distribution and rupture properties of intermediate-depth earthquakes (70–300 km) provide insights into the interior stress state of the subducting plate, its petrological composition, and the subduction history. Here we evaluate the kinematic spatio-temporal rupture evolutions of four M7+ intermediate-depth earthquakes beneath Peru between 1997 and 2021 using teleseismic waveforms, which reveal similar rupture behavior over a limited depth range within the flat-slab segment. The intermediate-depth seismogenic zone is confined within a narrow band ~20 km thick near the slab surface, as also found in Pampean and Mexican flat slabs, contrasting to the broader seismicity distributions in the adjacent normally-dipping segments. The elongated earthquake ruptures in flat slabs with few aftershocks and the narrow, sparse seismicity bands are attributed to flexure from along-dip slab steepening and limited dehydration reactions within relatively dry flat-slab segments. Conversely, the diffuse seismicity in adjacent normally-dipping segments is likely associated with more widespread dehydration reactions. |
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| ISSN: | 2662-4435 |